linux-postmarketos-exynos5: upgrade to 6.1.24 (lts) (MR 4022)

The pmaports package will follow lts releases from now on.
Intermediate versions will be tagged in the
gitlab.com/exynos5-mainline/linux repo.

Also enable CONFIG_LRU_GEN while we are at it (but not
CONFIG_LRU_GEN_ENABLED for now).
[ci:skip-build]: already built successfully in CI